1. Field of the Invention
The present invention concerns the determination of the film-forming properties of a paste.
It may relate to a paste or dough obtained from cereal flour and in this case the apparatus according to the invention permits the ability of the flour to make bread or biscuits to be evaluated.
It particularly concerns, in the preferred application of the invention, a paste of chewing gum and more precisely bubble gum, and in this case the apparatus according to the invention permits the ability of this paste to form bubbles to be evaluated.
Hereinafter, and especially in the description, the application to a bubble gum paste will be discussed exclusively.
In relation to this subject it will be recalled that the essential characteristic of a bubble gum is its ability to form bubbles whilst being chewed by the person who has put it into his mouth.
This ability derives from the composition of the base gum, which forms the insoluble part of the bubble gum (the masticatory support) and to the properties of the starting materials used.
As a result, when a bubble gum manufacturer wishes to develop and put on the market a new base gum, he must determine the ability of the paste of this bubble gum to form bubbles under the effect of mastication.
2. Description of the Prior Art
From time to time, qualitative determinations of the ability of a bubble gum paste to form bubbles have been made by resorting to a group of experts who chew this paste, but the problems posed by such experiments, which are of necessity subjective and do not give true numerical results, will be readily understood.
It has also been proposed to make use of a traction machine which acts on a dumb-bell shaped test sample of bubble gum base gum. This is however a linear test, in other words according to only one axis, along which the traction is exerted, whilst the inflation of a bubble is a surface effect, which thus is dependent on two axes. The numerical results of a traction test do not therefore permit sufficiently precise determination of the ability of a gum for bubble gum to form bubbles.
In order to determine the said ability, apparatus intended for the evaluation of the ability of a flour or cereal dough to make bread or biscuits, for example a Chopin alveograph (from the company Chopin S.A.), has occasionally been used. In an alveograph of this sort a sample of paste is submitted to a pressure supplied by means of a column of water disposed above the alveograph proper, this pressure bringing about the inflation of a bubble of paste. The pressure variation caused by the formation of the bubble is determined during the inflation period by means of a column of mercury. The measurements obtained with apparatus of this type do not permit the properties of base gums for bubble gum to be ascertained in a satisfactory manner, owing to the performance of the apparatus.